1. Field
The present disclosure relates to a belt-driven starter-generator.
2. Background
In general, a vehicle includes a starter motor for driving an engine and an alternator for generating electricity using torque of the engine. In the starter motor, an ignition switch is connected to a battery power source through an operation of a driver when the vehicle is started, and thus driving force generated by supply of power to the starter motor rotates the engine so that the vehicle start.
On the other hand, the alternator is connected to a drive portion of the engine to generate alternating current power by rotation of a rotor in a state in which a magnetic field is formed through the driving force of the engine, and the alternating current power is converted using a rectifying device so as to charge the battery.
Both of the starter motor and the alternator have a structure configured of a stator and a rotor. Accordingly, since the starter motor and the alternator have a very similar structure, the starter motor and the alternator may function as either a generator or a motor according to application of force or power thereto.
In recent years, a belt-driven starter-generator (BSG) structure which can serve as both of a stator motor and an alternator by one structure has been actively pursued. In the belt-driven starter-generator, a pulley belt is coupled to an upper end of a rotary shaft rotated by a motor. Specifically, after a woodruff key is laterally inserted into the rotary shaft, the pulley belt is assembled and fixed by fastening a nut thereto.
However, when the motor is driven at a high speed, the fixed coupling of the nut to the pulley belt becomes loose, resulting in malfunctions and deteriorated reliability. Further, there is difficulty in assembling the pulley belt since the woodruff key is laterally inserted into the rotary shaft.